Indian satellite AstroSat discovers one of the earliest galaxies of Universe

Indian satellite AstroSat discovers one of the earliest galaxies of

Question: Consider the following statements:
(1) AstroSat has detected extreme UV light from a galaxy called AUDFs01.
(2) The galaxy AUDFs01 is located in the Hubble Extreme Deep field, 9.3 billion light-years away from Earth.
Of the above correct statement/s is/are:
(a) Only 1
(b) Only 2
(c) Both 1&2
(d) None of the above
Answer: (c)
Related facts:

  • A global team led by scientists of the Inter University Centre for Astronomy and Astrophysics (IUCAA) has discovered one of the earliest galaxies called AUDFs01 using AstroSat.
  • The galaxy is located in the Hubble Extreme Deep field, 9.3 billion light-years away from Earth.
  • The team comprises scientists from India, Switzerland, France, USA, Japan and Netherlands.
  • This is the first time that star-forming galaxies have been observed in this extreme UV environment.

Hubble eXtreme Deep field (XDF):

  • Hubble eXtreme Deep Field (XDF) is a portion of space that contains approximately 5,500 galaxies, the oldest of which are seen as they were 13.2 billion years ago, recorded by the Hubble Space Telescope for over 10 years.

Background:

  • Earlier, NASA’s Hubble Space Telescope (HST), which is significantly larger than the Ultra Violet Imaging Telescope (UVIT) on Astrosat, did not detect any UV emission (with energy greater than 13.6 eV) from this galaxy because it is too faint.
  • AstroSat/UVIT was able to achieve this unique feat because the background noise in the UVIT detector is much less than the ones on HST

Significance:

  • This is a very important clue to how the dark ages of the Universe ended and there was light in the Universe.
  • Since UV radiation is absorbed by Earth’s atmosphere, it has to be observed from space for better understanding.

AstroSat:

  • AstroSat is the first dedicated Indian astronomy mission aimed at studying celestial sources in X-ray, optical and UV spectral bands simultaneously.
  • AstroSat with a lift-off mass of 1515 kg was launched on September 28, 2015 into a 650 km orbit inclined at an angle of 6 deg to the equator by PSLV-C30 from Satish Dhawan Space Centre, Sriharikota.
  • The minimum useful life of the AstroSat mission is expected to be 5 years.
  • One of the unique features of AstroSat mission is that it enables the simultaneous multi-wavelength observations of various astronomical objects with a single satellite.

By-Amar Mani Upadhyay

Links:
https://indianexpress.com/article/technology/science/global-team-led-by-iucaa-scientists-marks-a-major-breakthrough-6568281/
https://www.isro.gov.in/astrosat-0